Add files for comparison of energies of the golden track from hcana and

the best track from Engine.

    comp_gtrk_e.C -- script for the comparison,
    engine_class.h and engine_class.C -- class obtained from Engine root file,
    hcana_class.h and hcana_class.C -- class obtained from hcana root file,
    make_class.C -- a script to generate the class files.